Add gohacks.Slice/StringHeader.

See https://github.com/golang/go/issues/19367 for rationale. Note that the
upstream decision arrived at in that thread, while useful for some of our use
cases, doesn't account for all of our SliceHeader use cases (we often use
SliceHeader to extract pointers from slices in a way that avoids bounds
checking and/or handles nil slices correctly) and also doesn't exist yet.

PiperOrigin-RevId: 358071574

1 files changed, 6 insertions, 7 deletions

diff --git a/pkg/flipcall/flipcall_unsafe.go b/pkg/flipcall/flipcall_unsafe.go
index 580bf23a4..613ed8943 100644
--- a/pkg/flipcall/flipcall_unsafe.go
+++ b/pkg/flipcall/flipcall_unsafe.go
@@ -61,13 +61,12 @@ func (ep *Endpoint) dataLen() *uint32 {
 // - Writers must not assume that they will read back the same data that they
 // have written. In other words, writers should avoid reading from Data() at
 // all.
-func (ep *Endpoint) Data() []byte {
-	var bs []byte
-	bsReflect := (*reflect.SliceHeader)(unsafe.Pointer(&bs))
-	bsReflect.Data = ep.packet + PacketHeaderBytes
-	bsReflect.Len = int(ep.dataCap)
-	bsReflect.Cap = int(ep.dataCap)
-	return bs
+func (ep *Endpoint) Data() (bs []byte) {
+	bshdr := (*reflect.SliceHeader)(unsafe.Pointer(&bs))
+	bshdr.Data = ep.packet + PacketHeaderBytes
+	bshdr.Len = int(ep.dataCap)
+	bshdr.Cap = int(ep.dataCap)
+	return
 }
 
 // ioSync is a dummy variable used to indicate synchronization to the Go race